When an image is implemented using a projector and a projection surface, the image projected by the projector needs to be corrected based on geometric information of the projection surface. Since the image projected on the projection surface can be distorted by the geometric structure of the projection surface (e.g., the slope of the entire projection surface, the shape of the surface, structures installed on the surface and the like), distortion of the image generated by the geometric structure needs to be offset through correction of the image.
The correction which offsets distortion of an image generated by the geometric structure of the projection surface can be largely divided into two types. Specifically, the correction can be divided into a ‘global correction’ considering the overall arrangement state of the projection surface and a ‘local correction’ considering a local structure of the projection surface.
Here, the ‘global correction’ is a correction for offsetting distortion of an image that can be generated when the projector is arranged not to be perpendicular to the projection surface, and this is also referred to as a keystone correction or a corner pin correction.
In addition, the ‘local correction’ is a correction for offsetting local distortion that can be generated when the projection surface is not a smooth plane and a stricture is installed on the projection surface, and this is also referred to as a warping correction.
On the other hand, describing the ‘local correction’ more specifically with reference to FIG. 1, a conventional ‘local correction’ corrects an image through a method of independently controlling (independently moving) a plurality of feature points after mapping the feature points on an image to be projected. For example, as shown in FIG. 1, an image is corrected through a method of independently controlling a plurality of vertexes (movement of a feature point does not influence other feature points) after mapping a mesh and a plurality of vertexes (function as a plurality of feature points) on an image to be projected.
However, such a conventional method may excessively distort an image more than needed according to a moving distance of a single feature point, and excessive input information is needed in order to implement a smooth image when the feature point is moved based on input information of a user. In addition, when an additional feature point is mapped on the image, further more excessive input information is needed in order to implement a smooth image.
Accordingly, a new image correction technique capable of solving these problems is required.